The Guardian

Doctors warn excessive intake can pose risks for some patients and say medical advice needs to be more specific

The common advice to drink plenty of water when ill is based on scant evidence and can actively harm chances of recovery, doctors have warned.

Medics at King’s College hospital NHS foundation trust, in London, raised the alarm after they treated a patient with hyponatremia – abnormally low sodium – from drinking too much water to help with a recurring urinary tract infection.

Overwhelming majority of people agree the government should legislate to stop chemicals polluting the Great Barrier Reef

More than two-thirds of Australians think the condition of the Great Barrier Reef should be declared a “national emergency” and support much stronger measures to protect it than are now being considered.

On Thursday the government released its report on the reef to Unesco, which was a condition of the reef being excluded from the UN body’s “world heritage in-danger” list. The government reported slow progress on the key issue of water quality and the failure of a major plank in the plan – slowing tree clearing in Queensland.

Tree campaign groups across Sheffield have been at pains to garner expert inputs to substantiate their very clear arguments against the Sheffield chainsaw massacre (Letters, 29 November). The Woodland Trust is a longstanding critic of the Sheffield “Streets Ahead” programme and its epic and disastrous plans for street tree “management”. Equally, the Sheffield Wildlife Trust has not been shy about its deep reservations. More recently, the Arboricultural Association has felt compelled to take a position. It is insulting to condemn them as “fanatics”.

Campaigners do not advocate saving every tree and have a clear position on the removal of the dead and the dangerous. Yet we live in a post-truth, post-factual world. Perhaps then we should be unsurprised when finding some rot and a little deadwood are being cast in the way of constructive dialogue.

From an Arctic expedition to working in a studio in the school of biology and environmental science at University College Dublin, artist Siobhan McDonald collaborates with researchers to broach subjects at the edges of current scientific knowledge

• Crystalline, curated by Helen Carey, will open at the Centre Culturel Irlandais, Paris, on 26 January 2017
  

Energy and climate targets are ‘well within reach’ but the transport sector is lagging behind

EU countries are on track to meet their 2020 targets for renewable energy and emissions cuts but could fall short of ambitious longer-term goals, the European Environment Agency (EEA) said on Thursday.

“The EU’s 2020 targets on energy and climate are now well within reach,” EEA executive director Hans Bruyninckx said.

Environmentally friendly groups at Companies vs Climate Change said they will work to make sure Trump won’t undo all the progress the country has made

From his claim that global warming was a gigantic hoax masterminded by China to his promise to pull the United States out of the landmark Paris agreement, Donald Trump’s surprise election win was widely decried by those who feared that recent progress in tackling climate change was about to come undone.

Related: Donald Trump presidency a 'disaster for the planet', warn climate scientists

The last Tasmanian tiger, or thylacine, is said to have died in 1936 and was declared extinct in 1986. The Thylacine Awareness Group claims there have been 5,000 reported sightings of thylacines in the past 80 years, however, they do acknowledge video evidence is ambiguous

• Footage courtesy of Thylacine Awareness Group YouTube channel
• Tasmanian tiger sightings: ‘I represent 3,000 people who have been told they’re nuts’
  

Efforts to curb tree clearing have failed, the government admits in its update to Unesco on work to save the world heritage site

Australia needs to work faster on lifting water quality to save the Great Barrier Reef, according to its first progress report to Unesco since the world heritage site was spared an “in-danger” listing.

The report admitted that a key plank of Australia’s conservation plan – land-clearing reforms in Queensland to staunch water pollution – had failed. It also highlighted climate change, which is the biggest threat to the reef and led to the worst recorded coral bleaching in its history this year, but which the plan makes no attempt to address.

Waitrose, John Lewis and Argos among the first users of a new biomethane fuel for gas-powered trucks, reports BusinessGreen

Gas-powered lorries laden with Christmas parcels are set to have a lighter carbon impact this season thanks to the launch today of a new renewable fuel from CNG Fuels.

Retailers including John Lewis, Argos and Waitrose have already confirmed some of their long-distance lorries will run on the green gas – a renewable biomethane fuel derived from food waste – which is up to 40% cheaper than diesel and emits 70% less carbon dioxide, CNG Fuel says.

Through the Export-Import Bank, the Obama administration has spent nearly $34bn on dirty energy plants in countries from India to Australia to South Africa

Seemingly little connects a community in India plagued by toxic water, a looming air pollution crisis in South Africa and a new fracking boom that is pockmarking Australia. And yet there is a common thread: American taxpayer money.

Through the US Export-Import Bank, Barack Obama’s administration has spent nearly $34bn supporting 70 fossil fuel projects around the world, work by Columbia Journalism School’s Energy and Environment Reporting Project and the Guardian has revealed.

Leaves and branches can slow air currents and cause pollutants to settle, says health watchdog

City trees, popularly thought to remove pollutants and improve urban life, may also increase the amount of foul air that people breathe, says the UK body which gives independent health guidance to national and local government.

“Leaves and branches slow air currents, causing pollutants to settle. They may also act as sinks for particulates and chemicals that may have direct or indirect effects in air quality. Air quality [under trees] may deteriorate at street level near vehicles,” says the National Institute for Health and Care Excellence (Nice) in new draft guidance for local government to combat air pollution.

Unchecked global warming is greatest threat to 21st-century security where mass migration could be ‘new normal’, say senior military

Climate change is set to cause a refugee crisis of “unimaginable scale”, according to senior military figures, who warn that global warming is the greatest security threat of the 21st century and that mass migration will become the “new normal”.

The generals said the impacts of climate change were already factors in the conflicts driving a current crisis of migration into Europe, having been linked to the Arab Spring, the war in Syria and the Boko Haram terrorist insurgency.

Wolsingham, Weardale Most hedgerow blackthorns are brutally trimmed but these small trees, unpruned and unharvested by birds, are laden with fruit

In early May, this blackthorn thicket had been smothered in the most spectacular display of blossom that I had ever seen and I made a mental note to return in autumn, to see if it had fulfilled its promise.

I’d intended to return sooner. Now it felt like the first real day of winter, and my breath turned to steam in the icy wind. In the shade of the trees beside the beck, where deep shadows would linger all day, fallen leaves were fringed with frost crystals.

Start to tourism season prompts environment minister to override federal law and allow the nets in NSW

Josh Frydenberg overrode federal law to give the go-ahead to lethal shark nets in northern New South Wales to save the local tourist industry and nipper clubs.

The environment minister has argued that there was a “national interest” in installing the controversial nets because, with the tourism season about to start, surf shops were experiencing decreased sales and nipper clubs had fewer registrations.

Malcolm Turnbull says ‘mechanisms’ to meet 2030 Paris emission reduction targets may need to be examined

Malcolm Turnbull has acknowledged the looming review of the Direct Action climate policy in 2017 “may result in some changes” to the federal renewable energy target.

The prime minister’s hedged observation on Thursday morning comes ahead of the release of the preliminary findings of the Finkel energy security review determining whether the national electricity market can deliver reliable base load power while meeting Australia’s climate change commitments.

Variable speed limits, removal of speed bumps and ‘no idling’ zones near schools among recommendations

Speed bumps should be removed, speed limits made variable on England’s motorways, sometimes dropping as low as 50mph, and a congestion charge considered in more cities to cut air pollution and save lives, health experts have said.

The National Institute for Health and Care Excellence (Nice) released a series of recommendations on Thursday which it said would “promote a smoother driving style” and help keep emissions down.

Greg Clark welcomes 700-job factory, the first to produce 75m-long blades for a new generation of offshore windfarms

The first 75-metre-long blades destined for windfarms off the UK’s coast will roll out of a factory in Hull when it officially opens on Thursday.

The inauguration of the Siemens plant at the city’s Alexandra Dock employs 700 people and was hailed by campaigners as an example of how curbing carbon emissions could create jobs.

Victorian woman spends two days in hospital after being stung on neck off Fitzroy Island

A female snorkeller is lucky to be alive after suffering heart failure following an Irukandji jellyfish sting in far north Queensland.

The 39-year-old Victorian woman was snorkelling off Fitzroy Island last Friday when she was stung on the neck by the deadly, thumbnail-sized jellyfish.

The Thylacine Awareness Group is ‘dedicated to the research, recognition and conservation of our most elusive apex predator’ – officially extinct since 1936

Six years ago Neil Waters moved to Tasmania. There, he says, he had a “brief encounter” with a thylacine, the carnivorous marsupial known as the Tasmanian tiger, declared extinct in 1986.

Two years later, in January 2014, he was doing work on his house when a smaller animal walked up a dirt track leading out of a tin mine and past his bedroom window.

New analysis of nine species that ‘walk’ by night on shallow reefs shows their range is much smaller than was known

Bizarre “walking sharks” are at a greater risk of extinction than previously thought, with new information about their distribution leading researchers to expect greater efforts to protect them from human threats such as fishing and climate change.

Bamboo sharks include nine species of sharks that swim and “walk” in shallow waters around northern Australia, Papua New Guinea and parts of Indonesia. In 2013 a new species of the genus was found in Indonesia.